JPH01225639A - Heat-sealable film for packaging material - Google Patents

Abstract

PURPOSE:To provide the title film excellent in tearability, bursting property, etc., by molding a mixture comprising a carboxylated ethylene/vinyl acetate copolymer, a styrene polymer and a high-density polyethylene in a specified weight ratio. CONSTITUTION:15-50wt.% at least one carboxylated ethylene/vinyl acetate copolymer (A) (e.g., maleic acid-modified ethylene/vinyl acetate copolymer) is mixed with 10-60wt.% at least one styrene (co)polymer (B) (e.g., polystyrene resin) and 15-40wt.% at least one high-density polyethylene (C) in an amount to give a total of 100wt.%. The obtained polymer mixture is molded to produce a heat-sealable film for packaging materials. This film can be desirably used as a heat-sealable adhesive layer provided on a base of a packaging material of a type in which the contents are taken out of it by partially breaking it.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a heat sealable film useful as a packaging material.

More specifically, packaging in which the contents are removed by tearing the packaging bag, such as sealed bags and strip packaging;
P T P (Press Through Pack
) Packaging in which the bottom of the container is pressed with the tip of a finger to rupture the lid such as aluminum foil to remove the contents, or aluminum foil pouches filled with fruit juice, etc., or plastic films that are easily crushed. When opening, for example, a brick-shaped paper container with a small window in a part of the wall of the package, the contents are sucked out by piercing the package with a straw at a specific point. The present invention provides a heat-sealable film for packaging materials that exhibits excellent physical properties as a heat-sealable adhesive layer provided on a base material for a package whose contents can be taken out by partially destroying it.

(Prior art) Seal bags, stick packaging, bellow packaging, strip packaging, blister packaging, PTP packaging, brick containers, etc. are used as individual packaging forms for packaging pharmaceuticals, foods, machinery/electronic parts, etc. Some products are based on the assumption that the package wall will be destroyed when the package is opened. The base materials for these packaging bodies include metal foils such as aluminum foil and stainless steel foil, papers such as imitation paper, high-quality paper, and glassine paper, or various plastic films, either singly or in a laminate of two or more. It is used. To form a package, the same packaging base materials or different types of packaging base materials are assembled by combining and bonding together.Usually, the adhesive method used is coating or lamination. This is accomplished by heat-sealing any part of the heat-sealable adhesive layer provided on the entire surface or part of the base material.

Conventionally, the heat-sealable adhesive layer provided on the packaging base material is coated with a thermoplastic resin composition or paint, and has a thickness of several microns. .

However, in recent years, heat-sealable thermoplastic resin films have been developed to improve heat-sealing strength and stabilize packaging quality, and especially in blister packaging and PTP packaging, to improve curling properties after heat-sealing. A method of using a composite base material with a heat-sealable adhesive layer by fusing it to a base material for packaging or pasting it with an adhesive has become popular. Polyolefins such as polyethylene and polypropylene, copolymers of olefins such as ethylene and propylene, or copolymers of these olefins and other α-olefins, such as butene-1, hexene-1,4-methylpentene-1, octene-1 Monovalent or polyvalent metal ions such as sodium ions or zinc ions, such as copolymers with 1 etc., metal salts of polymers having carboxyl groups such as ethylene-(meth)acrylic acid copolymers, etc. Ionomers composed of vinylidene chloride copolymer, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, ethylene-vinyl acetate copolymer (EVA)
) and the like are commonly used as heat sealable films for that purpose.

(Problems to be Solved by the Invention) As mentioned above, in a package in which the contents are taken out by destroying at least a part of the package upon opening, the opening method differs depending on the use. Various requirements are required for the heat-sealable film for forming the heat-sealable adhesive layer provided, depending on the purpose.

For example, if the target packaging is a sealed bag, stick packaging, billow packaging, strip packaging, blister packaging, etc., opening is done by tearing the packaging bag, so the packaging base material is aluminum foil, imitation paper, glassine paper, etc. A material with good tearability, such as a polypropylene film that has been subjected to a stretching process or a cutting process, is used, but the heat sealing strength of the heat sealable film to constitute the heat sealable adhesive layer must be sufficiently high. Of course, if the packaging bag does not have good tearability, the contents may spill due to the impact when the packaging bag breaks due to tearing, or the broken area may become irregular, making it difficult to remove the contents. Problems arise such as not being carried out.

In addition, if the target package is a blister package or PTP package, the packaging form will be a processed molded plastic sheet with a pocket formed into a container part for storing the contents, and a lid part. The container consists of two parts: a base material for the packaging body and a plastic sheet made of polyvinyl chloride or polypropylene, and the lid material is made of aluminum foil, glassine paper, white cardboard, etc. The lid and container are often heat-sealed using an adhesive layer on the lid, and the lid is opened by rupturing the lid material directly or indirectly, such as by pressing the bottom of the container with your fingertips. There is.

Therefore, the heat-sealable film laminated to the base material that becomes the M material exhibits sufficient heat-sealing strength to the base material of the lid material and the plastic that is the material of the container, and reduces the rupture of the base material of the lid material. must not.

For example, plastic film, aluminum foil, paper, etc. placed on a small window in the container wall made of paper base material, such as brick-type containers mainly used for packaging liquids such as fruit juice and soup. Containers of the type where the contents, mainly liquid, are taken out by piercing a straw and tearing the straw, are made of a heat-sealable packaging film made by laminating a paper base with a small window and a heat-sealable film. When the sealing film is used as a heat-sealing adhesive layer and also as a sealing film for an outlet, the heat-sealing film has a strength that does not break during handling, and
It is necessary that it can be easily penetrated with a straw or the like.

As mentioned above, there are various methods and applications for packaging that is opened by destruction, so the heat-sealable film used as the heat-sealable adhesive layer of the base material for the package also has the heat-sealability that is the original purpose. In addition, it is necessary not to impair the destructive properties of each.

However, although heat-sealable films for packaging materials are used depending on the packaging form, these heat-sealable films are used differently according to various methods and uses even if the base material is the same, and the process is very complicated. However, the current situation is that incorrect application is unavoidable.

(Means for Solving the Problem) The present inventors have widely used a heat-sealable adhesive layer provided on a base material for a package whose contents are taken out by destroying at least a part of the package upon opening. As a heat-sealing film for packaging materials that can be used, ■ it has strength that will not cause damage under normal handling, and ■ it is not only self-heat sealable, but also can be used on metal substrates such as aluminum foil, glassine paper, and imitation paper. , paper such as white cardboard, and polyvinyl chloride,
It has good heat sealability for base materials used in packaging such as polyethylene, polypropylene, polystyrene, polyethylene terephthalate, and various other plastic films or sheets.
When laminated by adhering to aluminum foil used as a lid material in TP packaging, etc., the bursting strength of the aluminum foil does not increase too much, and it ruptures easily due to the pressure on the bottom of the container, making it easy to remove the contents. ■Easy tearability, for example, when tearing a package laminated with kraft paper and used as a seal bag as a packaging base material, the tearing strength of the kraft paper is not increased too much and the kraft paper is easily torn. The aim was to develop a resin composition that can be easily torn along the direction and easily pierced with a straw when used as a sealing film for everyday liquids such as brick packaging. The present invention was arrived at through research.

That is, the present invention uses 15 to 50% of at least one type of ethylene/vinyl acetate copolymer (A) having a carboxyl group.
(overlapping %, the same applies hereinafter), 10 to 60% of at least one styrene (co)polymer (B) and at least If! High density polyethylene fcl l 5~4
0% [However, (Al + fBl + fcl=100
A heat-sealable film for packaging materials formed by molding a polymer mixture (Di), which has a polymer mixture of It has sufficient heat sealability for materials, is easily ruptured,
The present invention was completed by discovering that it has properties such as being easily tearable and being easily inserted as a sealing film for straw insertion openings, etc.

In particular, it has been found that the heat-sealable film for packaging materials of the present invention exhibits significantly less curling during heat-sealing.

M for forming the heat sealable film for packaging materials of the present invention
As the ethylene-vinyl acetate copolymer + Al having a carboxyl group, which is a component of the H fat mixture 1jff (D), an ethylene-vinyl acetate copolymer having a carboxyl group chemically bonded is suitable. There are no particular restrictions on the method of introduction, i.e. (meth)acrylic acid,
A method of copolymerizing polymerizable unsaturated carboxylic acids such as crotonic acid, maleic acid, fumaric acid, itaconic acid, and citraconic acid or their anhydrides as a third component during the polymerization of ethylene-vinyl acetate copolymer; A method in which vinyl acetate copolymer is subjected to graft polymerization or Gurarad copolymerization with other unsaturated polymerizable monomers, and a method in which dicarboxylic acids such as maleic anhydride, fumaric acid or itaconic acid are added to ethylene-vinyl acetate copolymer. A carboxyl group is introduced by arbitrarily selecting a conventional method such as. In addition, for example, the hydroxyl group of the partial hydrolyzate of ethylene-vinyl acetate copolymer can be converted to maleic acid, fumaric acid,
A synthetic method such as a method of introducing a carboxyl group by half-esterification with a polyhydric carboxylic acid such as itaconic acid may also be used.

Further, the ethylene-vinyl acetate copolymer may be copolymerized with other modifying monomers in addition to ethylene, vinyl acetate, and the carboxyl group-containing monomer.

Any of these ethylene-vinyl acetate copolymers can be used, but the degree of compatibility with the styrene (co)polymer + B) combined to produce the resin mixture (D), melting point, and secondary transition An appropriate one may be selected in consideration of various physical properties of points, etc.

The second component of the resin mixture (D) for forming the heat-sealable film for packaging materials of the present invention is the styrene (co)polymer (B). In addition to widely commercially available copolymers and copolymers with acrylonitrile, there are also copolymers with unsaturated carboxylic acid monomers and copolymers with various other comonomers. Various physical properties can also be obtained by different polymerization modes such as random copolymerization, graft copolymerization, and block copolymerization. Vinyl copolymer (Al and high density polyethylene (C)
It is necessary to select it appropriately in consideration of the various physical properties of No. 1.

Resin mixture for forming the heat-sealable film for packaging materials of the present invention (high-density polyethylene, which is the third component of DJ)
Although any commercially available product can be used for C), an appropriate product may be selected depending on the degree of compatibility with the above two components.

In forming the heat-sealable film for packaging materials of the present invention, various compounding agents generally used in the production of plastic films, such as dye pigments, fillers, lubricants, blowing agents, and antioxidants, are added to the resin mixture +01. Addition of agents, plasticizers, etc. can be carried out arbitrarily as required. For example, if a foaming agent is added to the resin mixture (b) and molded, a heat-sealable foamed film can be obtained, but the film will not have cushioning properties. Therefore, it is expected to improve adhesion to uneven substrate surfaces, and most of the measures used for ordinary plastic films can be applied as is.

There are no particular limitations on the method of forming the heat-sealable film used in the heat-sealable film for packaging materials of the present invention, including casting methods, inflation methods, T-die extrusion methods,
Any conventional film forming method such as a calendaring method can be applied, and most conventional processing methods can also be applied, such as adding directionality to the rupture properties by adding stretching. It is also possible to form a multilayer film by coextruding the heat-sealable films for materials or, if necessary, with other heat-sealable films.

There is no particular limit to the thickness of the heat-sealable film, and it should be set appropriately considering the type, thickness, and strength of the packaging base materials to be laminated, but it should be determined based on the film strength and molding method. Generally, a range of 5 to 50 μm is preferable.

As mentioned above, there are no restrictions on the packaging base material on which the heat-sealable film for packaging materials of the present invention is to be laminated, including metal base materials such as aluminum foil, papers such as glassine paper, imitation paper, white cardboard, etc. It can be applied to base materials used for packaging such as various plastic films or sheets such as polyvinyl chloride, polyethylene, polypropylene, polystyrene, and polyethylene terephthalate.

There are no particular restrictions on the lamination process of the heat-sealable film for packaging materials of the present invention and the packaging base material, and the device may be any method such as a flat plate press method or a roll press method.
A known laminator can be applied as is.

As a lamination method, it is possible to directly heat and press the heat-sealable film for packaging materials of the present invention to the packaging base material to fuse it, or it is also possible to use a lamination adhesive for lamination. However, the dry lamination method is the most common. As the adhesive for lamination, any commercially available organic solvent-based or aqueous-based adhesive, or in some cases a hot-melt adhesive, can be used.

In particular, in the easily burstable packaging material of the present invention, the thickness of the heat-sealable film and the thickness of the aluminum foil are generally in the range of 10 to 50 μm and 5 to 30 μm, respectively, and the thickness of the composite material is in the range of 10 to 50 μm, respectively. A range of 15 to 60 μm is more preferable for easy rupture and anti-curl effect.

There is no particular limit to the thickness of the heat-sealable film, and it should be set appropriately taking into account the thickness and strength of the aluminum foil to be laminated, the thickness and price of the product packaging material, etc. However, there are restrictions from the film strength and the molding method, and as mentioned above, it is usually preferable to have a thickness in the range of 5 to 50μ.

There are no restrictions on the aluminum foil used in the easily burstable packaging material of the present invention, and either hard or soft aluminum foil can be used. There is no particular limit to the thickness, but as mentioned above, a thickness of 5 to 30 μm is preferable.
Aluminum foils with a μ range of 5 to 25 μ are preferable, however, considering that the strength of the entire material is improved by laminating with a heat-sealable film.

(Actions and Effects) The resin mixture for forming the heat-sealable film for packaging materials of the present invention (formerly the ethylene-vinyl acetate copolymer (A) having a carboxyl group has self-heat sealability and aluminum foil heat sealability for metal substrates such as glassine paper, imitation paper, white cardboard, and packaging materials such as various plastic films and sheets such as polyvinyl chloride, polyethylene, polypropylene, polystyrene, and polyethylene terephthalate. This ethylene-vinyl acetate copolymer with carboxyl groups (
It depends on Al.

Resin mixture of heat-sealable film for packaging materials of the present invention (Dl
The styrene (co)polymer (8), which is the second component, has the effect of imparting brittleness to the heat-sealable film obtained by molding the resin mixture (Dl) and reducing its burst resistance value.

High-density polyethylene (C), which is the third component of the resin mixture (Dl) for forming the heat-sealable film for packaging materials of the present invention, contributes to the tearability of the heat-sealable film for packaging materials, and especially The resin mixture (D) of the invention has the property that it can be torn linearly in any direction.

The resin mixture (D) for forming the heat-sealable packaging film of the present invention is an ethylene/vinyl acetate copolymer (A115 to 50%) having at least one type of dicarboxyl group.
, at least one styrene (co)polymer + B) 10~
60% and at least one high density polyethylene (
C) 15-40% [However, (Al + (B) +
(C) = 100%], but when the mixing ratio of the ethylene-vinyl acetate copolymer (A) having a carboxyl group is 15% or less, the heat sealing obtained by molding the resin mixture (D゛) On the other hand, when the heat sealability of the heat sealable film increases to 50% or more, the heat sealability improves and the adhesive strength increases, but as the strength of the heat sealable film increases, the elongation also increases, making it difficult to tear or burst. This is unsuitable because the resistance increases.

In addition, if the mixing ratio of the styrene (co)polymer fB) is less than 10%, the brittleness of the heat-sealable film obtained by molding the FM4 mixed finger compound will decrease, and the elongation will increase, so it will burst if it is torn. It becomes difficult for this to occur, and even if it does occur, it is incomplete, so if it is made into a package, the contents cannot be taken out smoothly.If it exceeds 60%, the brittleness becomes too large, making it impossible to form a film. Even if it disappears and can be molded, handling is difficult.

When the mixing ratio of high-density polyethylene (C) was 15% or less, the tearability of the heat-sealable film obtained by molding the resin mixture fD) decreased, and the film did not tear in any direction or burst. In some cases, the container often rips in one direction, leaving the container in its original state and making it impossible to remove the contents.

If it is more than 40%, the heat sealability will deteriorate and the required adhesive strength will not be obtained.

In addition to the above-mentioned characteristics, the heat-sealable packaging film of the present invention has a characteristic that it has a small tendency to shrink even when exposed to high-temperature atmosphere, which may cause deformation of the package or peeling of the adhesive surface. The loss due to the occurrence of such problems will be reduced.

The heat-sealing film is made of a resin mixture (DJ) that can be made from translucent to opaque depending on the composition, so when laminated on a packaging base material, it scatters reflected light and has the effect of creating a matte surface. Since the degree of opacity of the heat-sealed portion does not change, it is possible to create an appearance similar to that of a matte surface by laminating it on a glossy surface of aluminum foil, for example.

Hereinafter, the present invention will be explained in more detail with reference to examples.

[Example 1] 5305E Modic E-300H (carboxyl group-modified ethylene-vinyl acetate copolymer manufactured by Mitsubishi Yuka ■: melt index 2.5, specific gravity 0.95, Vicat softening point 43°C) 3
3 parts and Dialex HT-516 (polystyrene resin manufactured by Mitsubishi Monsanto Chemical Industries ■: melt index 2,
2. Specific gravity 1.05, Vicat softening point 94°C) 50 parts and Hizex 5305E (Mikata Petrochemical Industry 11!
A resin mixture was prepared by mixing 17 parts of R high-density polyethylene (melt index 0.8, specific gravity 0.95, Vicat softening point 122°C), and molded using a blown film extruder at a cylinder temperature of 160°C and a die. A heat-sealable film having a thickness of 30 μm was produced at a temperature of 197° C.

When the tip of a polyethylene straw with a diameter of 31 mm was pressed against the obtained film and a slight pressure was applied, a circular hole was easily opened along the tip of the straw and penetrated through the film.

This film was coated with a 20μ thick soft aluminum foil using a polyurethane two-component dry lamination adhesive (
Manufactured by Takeda Pharmaceutical Company, Takelac A310/Takenate A
-3) to create a packaging base material with a thickness of approximately 50μ.

This packaging base material was put together with the heat-sealable film sides facing each other, and the heat-sealing temperature was 130°C and the pressure was 3g/cv*"
,,The heat seal was applied with a pressure of 1 second, and when the heat sealed part was torn by hand, it was easily torn linearly in any direction, and the cut edges were clean and clean with no serrations or fluff. .

In addition, the above-mentioned packaging base material was heat-sealed to a polypropylene sheet with a thickness of 250μ at a temperature of 180°C and a pressure of 3g/am.
A sample for a heat sealability test was prepared by heat sealing under the conditions of pressurization time of 1 second. When a 180 degree peel test (15 mm) was performed on this sample, the weight was 1.38 kg. The heat sealing adhesive strength required varies depending on the application, but
Normally, 1kg for FTP packaging, strip packaging, etc.
If it is above, it is considered to be satisfactory.

In the same way, this packaging base material was heat-sealed to a hard vinyl chloride resin sheet with a thickness of 250μ at a temperature of 130°C and a pressure of 5 kg.
/c+f, heat sealing was performed under the conditions of pressurization time of 1 second,
A sample for a heat sealability test was prepared, and its peel strength at 180°C was measured to be 1.24 g.

In addition, for the samples heat-sealed on the two types of plastic base sheets mentioned above, the size of the curl was defined as the length of the chord when a 20 mm long sample piece draws an arc by curling, that is, the length of the chord at both edges at that time. Measured by the distance between. Practically speaking, it is preferable that the value is not less than 16-1, but in the case where the base material is a polypropylene sheet and a vinyl chloride resin sheet, it is 18.0 mm and 18.7 m, respectively.
-1 shift was obtained.

Next, the bursting strength (JIS P8112) and tensile strength per 15 mm of the packaging material were measured. Bursting strength is 2
If the tensile strength exceeds "Kg/cm", the FTP packaging becomes difficult to tear due to pressure, and the necessary strength for handling is said to be 2.0 g or more in terms of tensile strength.

The bursting strength of the packaging material in this example was 1.3 kg/cr.
A value of 2.6 kg was obtained for n' and tensile strength.

Furthermore, pockets for storing pharmaceutical capsules were formed on the 250μ thick polypropylene sheet and vinyl chloride resin sheet, and the packaging base material of this example was sealed under the same conditions as in the heat sealing strength test. The capsules were stored and heat-sealed to create FTP packages. All of them had sufficient strength as packages, and when the bottom of the container was pressed with the tip of a finger, the lid material burst easily and the capsules could be easily taken out.

[Example 2] In Example 1, a resin mixture was prepared by mixing 26 parts of Modic E-300H, 40 parts of Dialex HT-516, and 34 parts of Hizex 5305E, and a blown film extrusion molding machine was used. A 20 μm heat-sealable film was produced by molding in the same manner.

When the tip of a polyethylene straw having a diameter of 31 mm was pierced through the obtained heat-sealable film, it was easily penetrated as in Example 1.

The heat-sealable film was laminated with a soft aluminum foil having a thickness of 15 μm to prepare a packaging base material having a thickness of about 35 μm.

The properties of this packaging base material were measured in the same manner as in Example 1.

That is, the tearability of the sample obtained by heat-sealing the packaging base materials together was as good as in Example 1.

In addition, the heat sealing strength is 1 compared to polypropylene sheet.
．． 28kg, 1.15k for vinyl chloride resin sheet
g, and the curl degree was 17.g for each case of polypropylene sheet and vinyl chloride resin sheet.
It was 5+ms and 18.0mm.

Bursting strength and tensile strength are each 1.8 kg/c
rrf and 4.3 kg.

Next, the heat-sealable film of this example was laminated directly onto glassine paper with a thickness of 35 μm by passing it through a pressure roll at 180°C to prepare a packaging base material, but the tearability was good.
The heat seal strength is 1.04Kg and 1.0Kg for polypropylene sheet and vinyl chloride resin sheet, respectively.
g6 in 03, curl degree is 18.3mm and 1 respectively
8.8m layer, tensile strength and bursting strength are each 2
．． 7Kg.

and 1.46 g,/cs”.

[Comparative Example 1] Barden 1 was applied as a heat sealant for polypropylene sheets to the 20μ thick soft aluminum foil used in Example 1.
3-L (manufactured by Toyo Kasei Kogyo ■, chlorinated polypropylene solution, chloride 26% non-volatile content 30% toluene solution),
Dick Seal A-10 for vinyl chloride resin sheets
0Z-3 (vinyl chloride-vinyl acetate copolymer solution manufactured by Dainippon Ink Chemical Co., Ltd., methyl ethyl ketone/toluene solution with 25% nonvolatile content) was applied at a rate of 5 g/m'' (solid content) each, dried, and then A coated packaging base material used as a PTPM material was prepared, and its elastic properties were measured in the same manner as in Example 1.

Although the tearability was good, the heat sealing strength was low at 0.91 kg for the polypropylene sheet and 1.6 kg for the vinyl chloride resin sheet. The degree of curl is one type for each polypropylene sheet and vinyl chloride resin sheet. 8mm and 15.3m
- Both have major problems in the work process.

The bursting strength is 1.8 kg/cn for packaging substrates for polypropylene sheets. However, for packaging base materials for vinyl chloride resin sheets, the weight was 3.3 kg/cm.
However, the tensile strengths were 2 kg and 2.1 kg, respectively.

The above two types of packaging base materials were heat-sealed by replacing the base sheet, but neither showed any adhesiveness.

[Comparative Example 2J Modic E-300H, Dialex HT-516
and 12 parts of HIZEX 5305E, 50 parts
and 38 parts, a heat-sealable film with a thickness of 30 μm was produced in the same manner as in Example 1, and the film was laminated onto a soft aluminum foil with a thickness of 20 μm.
A packaging base material having a thickness of 0 μm was prepared, but this packaging base material exhibited almost no adhesive strength to either polypropylene sheets or vinyl chloride resin sheets with an adhesive strength of 0.3 kg or less.

[Comparative Example 3] The same process was carried out as in Example 1 except that the amounts of Modic E-300H, Dialex HT-516, and Hizex 5305E were changed to 60 parts, 23 parts, and 17 m, respectively. A sealing film was produced, and a packaging base material having a thickness of approximately 50 μm was also created.

The tip of a polyethylene straw with a diameter of 3 mm was pressed against the obtained heat-sealable film and pressure was applied, but the film did not penetrate easily and the straw was often bent.

The packaging substrate has poor tear properties, has high resistance and tends to become fuzzy at the cut end, and has a burst strength of 2.7 k.
g/cn? Therefore, a pocket for storing pharmaceutical capsules was molded into a polypropylene sheet and a vinyl chloride resin sheet in the same manner as in Example 1, and the packaging base material of this comparative example was used as a lid material to store capsules. When we created FTP packages by storing and heat-sealing each package, we found that all of them were strong enough to be used as packages, but the lid material did not burst easily even when pressed with a fingertip at the bottom of the container, and it was difficult to apply large pressure. When added, the container deformed, but the capsule could not be taken out easily.

[Comparative Example 4] The same process as in Example 1 was carried out except that the amounts of Modic E-300H, Dialex HT-516 and Hizex 5305E were changed to 60 parts, 23 parts and 17 parts, respectively. A heat-sealable film was manufactured, and a packaging base material with a thickness of approximately 50 μm was also created.

The resulting heat-sealable film was strong and highly elongated, and even when pressed with the tip of a straw, the film stretched and was difficult to penetrate. Tearability was also poor, and even if the aluminum foil was torn, the heat-sealable film layer was not easily torn.

Furthermore, in the measurement of rupture properties, a constant value could not be obtained due to the stretching of the heat-sealable film layer, so a pocket for storing pharmaceutical capsules was molded into a polypropylene sheet and a vinyl chloride resin sheet in the same manner as in Example 1. However, when the packaging base material of this comparative example was used as a lid material, capsules were stored and heat-sealed to create FTP packaging bodies. Even if the aluminum foil broke when pressed with the tip of a finger, the capsule could not be removed because it was connected by a heat-sealable film.

[Comparative Example 5] The process was carried out in exactly the same manner as in Example 1, except that the amounts of Modix E-300H, Dialex HT-516, and Hi-Zex 5305E were changed to 15 parts, 70 parts, and 15 parts, respectively. When attempting to produce a heat-sealable film, the film was so brittle that it frequently broke and could not be produced.

[Comparative Example 6] In Example 1, Sodic E-300H, Dialex HT-516 and Heise Tux 5'305 E
A heat-sealable film with a thickness of 30 μm was produced by the same process except that the blending amounts were changed to 33 parts, 57 parts, and 10 parts, respectively, and a packaging base material with a thickness of about 50 μm was produced. was creating.

- Depending on the direction of tearing, this packaging base material may have a high resistance and may become fluffy.

Moreover, the bursting strength is 1. '2kg/・cn? It was good.

However, in the same manner as in Example 1, a pocket for storing pharmaceutical capsules was molded into a polypropylene sheet and a vinyl chloride resin sheet, and the packaging base material of this comparative example was used as a lid material to store capsules. and heat seal it,
When I created an FTP package for each and pressed the bottom of the container with my fingertips, the lid material ruptured easily.The capsules could not be easily pushed out because several cracks were formed in a certain direction and remained in their original state. Ta.

[Comparative Example 7] The same process as in Example 1 was carried out except that the amounts of Modic E-300H, Dialex HT-516, and Hizex 5305E were changed to 33 parts, 17 parts, and 50 parts, respectively. A heat-sealable film was produced, and a packaging base material having a thickness of about 50 μm was also created.

The heat sealing strength of this packaging base material is 0.41k for polypropylene sheets and vinyl chloride resin sheets, respectively.
g, and 0.38 kg, hardly showing the required adhesiveness.

Claims (1)

[Claims] 1. At least one type of ethylene/vinyl acetate copolymer (A) having a carboxyl group, 15 to 50% (wt%,
The same shall apply hereinafter), at least one styrene (
Co)polymer (B) 10-60% and at least one high-density polyethylene (C) 15-40% [However, (A
) + (B) + (C) = 100%].